Metal forming



' 'July 8, 1969 c, ZELLER ET AL METAL FORMING Sheet 012 Filed March 22, 1967 =5 mum T E 2W V m5 N an 2 m H .hlly 8, 1969 c, ZELLER ET AL 3,453,850

METAL FORMING Filed March 22, 1967 I Sheet J of 2 INVENTORS: HUBERT [l ZELLEH WARREN W. J/KEIBLEE ATTYS United States Patent METAL FORMING Robert C. Zeller, Fort Wayne Road, and Warren W.

Weible, 635 Holgate Ave., both of Defiance, Ohio 43512 Filed Mar. 22, 1967, Ser. No. 625,259 Int. Cl. 321d 31/00, 22/J8 U.S. Cl. 72-71 18 Claims ABSTRACT OF THE DISCLOSURE The invention is directed to a new method of forming metal by an extrusion technique, using the term extrusion in a broad sense. A workpiece with at least one annular shoulder is rotated and a tool with an edge slanted with respect to the shoulder is placed in tangential engagement with the workpiece adjacent the shoulder, and moved along a path located in a plane perpendicular to the piece. The movement of the tool causes the slanted edge portion to place an axial component of force on the shoulder, the metal of which is then gradually forced over or extruded to increase the depth of the shoulder and form it at an angle. No metal need be removed from the workpiece unless the outer extremity of the enlarged shoulder is to be trimmed. The metal forming technique can be applied to a workpiece having a ring thereon forming opposed shoulders, with a tool engaging and forming both shoulders simultaneously.

This invention relates to metal forming and particularly to a method and apparatus for forming or extruding material at a shoulder of a rotating workpiece.

The invention enables a product of a particular predetermined shape to be formed from a metal stock or blank which is smaller than would otherwise be required. This is achieved because the use of the invention enables the metal to be formed without cutting metal from the stock or at least by reducing substantially the amount of metal cut therefrom, By reducing the size and weight of the stock or blank from which the product is made, the cost of the product is substantially reduced because of the lower cost of the stock.

The invention also has particular advantages when used to shape a ring of metal mounted around a metal rod or cylinder and specifically when the ring is of soft metal and the rod is of hard metal. Heretofore, Where a Workpiece of this nature was to be machined and specifically the soft ring formed, the workpiece was rotated and a cutting tool moved thereagainst to shape the ring as desired. However, with even a small amount of run-out of the work spindle or with even a slight degree of eccentricity in the hard metal rod adjacent the ring, the tool at times came into contact with the rod. Because of the extreme hardness of the rod, the cutting edge of the tool was damaged or, alternately, the ring was not shaped entirely as desired with edge portions blending with the surface of the rod if the tool was maintained slightly spaced from the rod to prevent damage to the cutting edge. With the invention, the tool is brought into tangential contact with the workpiece in a manner such that the tool cannot be damaged even though it may be pressed firmly against the hardened steel rod.

The above instances represent only two examples in which the invention can be applied in forming metal advantageously. Similarly, the specific applications of the invention subsequently described are only illustrative of the invention and are not to be considered at all limiting.

A more effective explanation of the invention will be attained when combined with specific examples to be discussed subsequently.

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It is, therefore, a principal object of the invention to provide a new method and apparatus for forming metal which minimizes or eliminates metal cut from the stock from which the product is to be made.

Another object of the invention is to provide a method and apparatus for accurately shaping a ring located on a body of harder material without damaging the tool or the body.

Numerous other objects and advantages of the invention will be apparent from the following detailed description of preferred embodiments thereof, reference bing made to the accompanying drawings, in which:

FIG. 1 is a side view in elevation, with parts broken away and with parts in section, of a tool holder, along with a tool, workpiece, and support embodying the invention;

FIG. 2 is a front end view of the tool holder and components of FIG. 1, taken along the line 22 of FIG. 1;

FIG. 3 is a view in perspective of a tool embodying the invention;

FIG. 4 is a bottom view of the tool;

FIG. 5 is a front end view of the tool;

FIG. 6 is a side view, with parts broken away and with parts in section, of a workpiece which can be formed advantageously by the method and apparatu according to the invention;

FIG. 7 is a greatly enlarged, fragmentary top view of the workpiece and the tool during a forming operation;

FIG. 8 is a fragmentary view in section taken along the line 88 of FIG. 7;

FIG. 9 is a view in elevation of a modified tool and workpiece before and after being formed in accordance with the invention; and

FIG. 10 is a fragmentary, perspective View of the tool used to form the workpiece of FIG. 9.

Referring to FIGS. 1 and 2, a workpiece, stock or blank is designated P. The workpiece is held in a suitable chuck 12 which is driven to rotate the workpiece in a counterclockwise direction as shown in FIG. 1 and as indicated by the arrow. The chuck and a drive unit 14 constitute part of a lathe, by way of example, or other machine designed for use with cutting tools.

A tool 16 according to the invention, to be discussed subsequently, is carried by a tool holder 18 which can be moved toward and away from the workpiece by guide means or ways 20 associated with a suitable support or table 22. The tool holder 18 includes a base 24 from which side plates 26 and 28 extend upwardly. A tool clamping block 30 is located between the side plates 26 and 28 and is pivotally supported at an upper end by a large pivot pin 32. The clamping block 30 cooperates with a vise block 34 afiixed thereto by machine screws 36 to form a keyway or groove 38 in which the tool can be received in a manner known in the art. The clamping block 30 is urged in a clockwise direction as shown in FIG. 1 to urge the tool 16 downwardly by means of a heavy spring 40 which engages a forward flat surface 42 of the clamping block 30. The spring 40 is held in compression between the surface 42 and an end of a retainer cup 44 which is supported against a cross bar 46 afiixed to upper corner portions 48 of the side plates 26 and 28 by suitable machine screws 50. An adjusting screw 51 adjusts the extent of compression of the spring 40. Movement of the clamping block 30 in the clockwise direction is limited by a stop screw 52 which abuts a rear surface 54 of the clamping block 30 when the block moves a predetermined amount in the counterclockwise direction. The stop screw 52 is threaded through a stop bar 56 affixed to the side plates by fasteners 58 and has a lock nut 60 which secures the position of the stop screw.

Referring to FIGS. 3-5, the tool 16 includes a block 62 of uniform cross section throughout most of its length. The top of the block 62 has a key or dovetail 64 which fits in and is held precisely by the keyway 38, although the tool can be formed as shown in our co-pending application entitled Tool and Tool Holder, filed on or about Mar. 16, 1967, with metal forming edges at both ends of the tool. The bottom of the block 62, in this instance, has runners or ridges 66 and 68 thereon. The inner corner of the runner 66 has a step or offset 69 and a small fillet 70 formed with a bottom surface 72 of the block 62. The inner corner of the runner 68 has a smaller step or offset 73 and a slanted surface 74 formed with the bottom surface 72. The runners 66 and 68 are not essential in all application but aid in shaping the workpiece to a desired configuration in the offsets thus provided. The runners also reduce friction between the tool and the workpiece when used and provide a smaller contact between the tool and the workpiece so that the position of the tool is less influenced by imperfections or irregularities on the surface of the workpiece.

A notch or recess 76 is formed in an end of the block 62 and has slanted or angled lower edge portions 78 and 80, the latter having a short, straight edge 82. The edges 78, 80, and 82 are formed by sides 84, 86, and 88 of the notch 76 meeting the bottom surfaces of the runners 66 and 68 or the bottom surface 72 of the block 62 in the event no runners are employed. As shown, the sides 84, 86, and 88 are in planes perpendicular to the bottom of the block. However, the sides can converge slightly in an upper direction toward the top of the block or can even diverge slightly without seriously affecting the performance of the tool for most applications.

The slanted edges 78 and 80, in this instance, terminate in a transverse edge 90 formed where a substantially vertical side 92 meets the bottom surface 72 between the runners 66 and 68 and specifically between the fillet 70 and the slanted edge 74. In this instance, the edge 90 performs a slight cutting function, trimming or shaving the top of the workpiece and specifically the portions formed upwardly by the slanted edge portions 78 and 80.

The workpiece or blank P is shown partly in section in FIG. 6. In this instance, the workpiece includes a cylindrical rod 94 of hard material and an annular ring 96 of relatively soft material afiixed in a groove 98 of the rod 94. By way of example, the rod 94 can be made of a hardened alloy steel while the ring 96 is made of soft brass. The ring 96 forms two annular side shoulders 100 and 102 upon which the tool 16 primarily acts. The final shape of the finished ring is indicated in dotted lines 104. In this example, the ring is both reduced in width and diameter, which could be accomplished by means of a conventional, cutting tool or shave tool. However, if such a tool were used and moved substantially radially against the workpiece in the usual manner, even the slightest run-out would either cause the side edges of the ring to extend slightly beyond the surface of the rod 94 or the tool would engage the rod 94 and be damaged or damage the rod. With the new tool, however, there is no cutting edge at all which actually contacts the rod 94 so that no damage can result.

In the forming operation, the workpiece P is rotated toward the tool, in a counterclockwise direction as shown in FIG. 1. The tool holder 18 is spaced from the workpiece with the tool clamping block 30 urged downwardly against the stop screw 52. The tool 16 is at an angle of approximately 30 to the horizontal in this instance and is then moved in a horizontal direction with the holder 18, along the ways 20, until the forward portions of the runners 66 and 68, just to the rear of the forward end surface of the tool contact the rod 94 tangentially on each side of the ring 96. The tool holder 18 is designed so that a line through the pivot 32 and the point of engagement of the tool and the workpiece P passes above the center of rotation of the workpiece, as shown in broken lines in FIG. 1. With this arrangement, any

tendency of the tool 16 to chatter during the forming operation is substantially overcome.

The tool holder 18 can then be further moved horizontally, toward the right in FIG. 1, preferably by a suitably controlled feed, at which time the clamping block 30 rotates a small amount in a counterclockwise direction, overcoming the force of the spring 40. The spring 40 maintains a substantial force on the tool 16, however, to hold it firmly tangentially against the rod 94. As the tool holder 18 moves further toward the right, the clamping block 30 moves further in a counterclockwise direction and the angle of the tool 16 relative to the horizontal increases somewhat. The tool also moves further onto the workpiece with the point of tangential engagement moving counterclockwise slightly.

As the tool 16 moves further onto the workpiece, the slanted edge portions 78 and begin to contact the outer corner portions of the shoulders 100 and 102, exerting a force on the shoulders having a component axially of the workpiece. This force causes the metal at the shoulders to tend to flow toward one another and, consequently, outwardly away from the surface of the rod 94. The tool can be fed at such a rate that the incremental portions of metal so formed are small so that relatively little force is required for the metal forming process. Further, while the formation of the metal is similar in some respects to that achieved with conventional extrusion dies, in this instance only small portions of the surface of the workpiece are engaged at any one time, rather than a ring around the entire workpiece, as it true with an extrusion die. Also with conventional extrusion, the columnar strength of the work is a definite limitation. A general rule of thumb is that no more than one-and-one-half diameters in length can be extruded or cold headed on conventional machines.

The force continues to be incrementally exerted axially in both directions on the shoulders 100 and 102 as the slanted edge portions 78 and 80 move further onto the workpiece. As the metal is deformed axially and outwardly, the outer extremities thereof are engaged by the cutting edge and are formed, as shown in FIG. 8. This produces the final smooth outer contour on the ring or band, as also shown in FIG. 7. The width of the band is reduced as the tool moves further onto the workpiece, as shown in FIG. 7, by the outer portions of the edges 78 and 80. With the edges of the tool tangential to the workpiece, the outer portions of the ring are forced axially to form a smooth continuation of the rod 94, without possible damage to the tool edges. The shoulders on the ring are formed by the offsets 69 and 73 of the edge portions 78 and 80, in the example shown, as they move toward tangential engagement with the workpiece. Even if the rod is eccentric, the spring 40 maintains the tool against the rod and enables the ring to form a smooth continuation of the rod surface.

As noted, there is never any cutting edge involved except the edge 90 and this does not come near the hardened rod 94, which could cause damage to the cut-ting edge. Only the slanted edge portions 78 and 80 actually engage the ring during the metal forming process, including small portions of the lower surfaces of the sidewalls 84 and 86. The sides 78 and 80 can converge in an upward direction somewhat to enable an additional area of the sides to engage the ring and deform it. The sides can also diverge to cause an even smaller portion of the sides adacent the edges 78 and 80 to engage the work. However, if the slides 78 and 80 should diverge excessively, then a cutting or shearing action by the edges 78 and 80 will tend to occur rather than a deforming or extruding action.

The included angle of the cutting edges 78 and 80 has been found to be most effectively about 28 which provides the maximum deformation of the metal with the minimum applied force and minimum transverse force on the workpiece. However, other included angles can be used, depending in particular on the shape of the desired final product. Included angles from about to about 50 are satisfactory, although angles as large as 90 can be employed. As the included angle increases, the transverse forces acting against the workpiece and also acting on the tool holder become increasingly larger. If single, slanted edge portions are used to act on a single shoulder of the workpiece, the angle of the slanted edge portion, relative to a plane through the shoulder, can be from about 5 to about 45".

A substantially different application of the invention is shown in FIGS, 9 and 10. Referring to FIG. 9, a metal blank shown in solid lines is formed to the outline shown in dotted lines to produce a pulley or sheave with substantially no metal removed from the blank. Without the removal of metal, a sheave of given size can be made from a much smaller blank, in size and weight, than heretofore possible.

In this instance, a workpiece or blank designated P comprises a cylinder or rod 106 of uniform diameter on each side of two annular rings 108 and 110 which form shoulders 112, 114, and 116, 118 respectively, The annular shoulders are acted on by a tool 120 in accordance with the invention, which tool can be held in a holder similar to that of FIGS. 1 and 2 and manipulated in the same manner. The tool 120 has two recesses 122 and 124 in this instance having lower work-deforming edge portions 126, 128, 130, and 132. The edges 128 and 130 slant substantially more than the edges 126 and 132. The sides extending upwardly from the bottom of the tool and forming the edge portions again can be substantially perpendicular to the bottom of the tool, or diverge or converge somewhat.

The recesses 122 and 124 form legs 134, 136, and 138 on the tool, which legs have extensions 140, 142, and 144 respectively. The leg extensions can engage the rod portions of the blank P prior to engagement of the shoulders 112-118 by the slanted edge portions 126-132. This enables the rod portion 106 of the blank to help support the tool as the tool is moved forwardly onto the rod portion and the slanted edges begin to engage the corner portions of the rings 108 and 110. As the tool moves onto the workpiece, the edges 126 and 132 deform the outer shoulders 112 and 118 relatively little. The edges 128 and 130, however, deform the adjacent shoulders 114 and 116 substantially more and extrude these portions outwardly to form the final flanges 146 and 148 shown in dotted lines. These flanges can be trimmed or shaved slightly by rear cutting edges 150 and 152, if necessary.

The actual sizes of the flanges can be controlled by the extent to which the tool is moved onto the workpiece. As the tool is moved further onto the piece, the flange portions 146 and 148 will retain their same general shape but will become narrower and smaller in diameter. If the tool were moved far enough that the cutting edges 150 and 152 were moved into tangential engagement with the rod 106, the flanges would disappear entirely.

The most important advantage with the method and tool according to the invention in forming products as shown in FIGS. 9 and 10 is the fact that substantially no metal is cut away and the initial blank employed to make the sheave can be much smaller than otherwise. The rod 106 which also forms the core of the sheave is not decreased in diameter and there is no metal removed between the flanges. The flanges 146 and 148, when finished, contain substantially as much metal as the original blank rings 108 and 110, except perhaps for a small amount or metal formed by the cutting edges 150 and 152.

In this instance, no runners are employed on the tool 120, which increases the friction slightly but otherwise has little effect. The only difference in results obtained is that with the tool of FIGS. 9 and 10, if moved far enough onto the blank, the rings 108 and 110 would b removed entirely. With the tool 16 of FIGS. 3-5, even if the tool were moved onto the work to the point that the rear cutting edge were tangential to the piece, the ring would still retain the contour as shown in FIG. 5, formed by the surface 72 and the adjacent fillet 70 and slanted surface 74.

Various modifications of the above described embodiments of the invention will be apparent to those skilled in the art, and it is to be understood that such modifications can be made without departing from the scope of the invention, if they are within the spirit and the tenor of the accompanying claims.

We claim:

1. A method of forming metal comprising rotating a workpiece having a raised portion forming an annular shoulder thereon, positioning a tool with a straight edge thereof at an angle relative to a plane through the shoulder which is perpendicular to the axis of rotation of the workpiece, moving the tool in a path toward the workpiece from a direction such that the workpiece rotates toward the tool and engaging the shoulder and maintaining a portion of the tool edge in tangential contact with the workpiece while engaging the shoulder with another portion of the tool edge to apply a force against the shoulder having a component parallel to the axis of the workpiece to cause incremental portions of the shoulder to move outwardly from the axis of rotation.

2. A method according to claim 1 further characterized by moving the tool into tangential contact with the workpiece adjacent the shoulder prior to engaging the shoulder with the tool edge.

3. A method of forming metal comprising rotating a workpiece having a raised annular portion forming a pair of annular shoulders, moving a tool with diverging lower slanted edge portions toward and above the tool in a path lying in a plane transverse to the axis of rotation of the workpiece and with the diverging lower slanted edge portions substantially tangential to the workpiece, and engaging both of the shoulders with said diverging slanted edge portions of said tool and urging the shoulders of the workpiece toward one another and outwardly from the axis of rotation of the workpiece.

4. A method according to claim 3 characterized by rotating the workpiece in a direction toward the tool.

5. A method according to claim 3 characterized further by engaging the tool tangentially with the workpiece on each side of the raised portion prior to engaging the shoulders with the edge portions.

6. A tool for extruding shoulders on a workpiece comprising a block having a notch of predetermined shape in one end thereof, said notch forming lower slanted workengaging edge portions on the block converging toward one another in a direction away from the end of the block, said edge portions lying generally in a common plane formed with a bottom surface of the block.

7. A tool according to claim 6 wherein said slanted edge portions form an included angle from about 10 to about 50.

8. A tool according to claim 6 wherein side walls of the notch are in planes perpendicular to the bottom of the block.

9. A tool according to claim 6 wherein at least one of said edge portions has an olfset therein.

10. Apparatus for incrementally extruding a shoulder on a rotating workpiece, said apparatus including a tool having an angular edge at a lower portion thereof, a tool holder positioning said tool at an angle with respect to a plane extending through the shoulder perpendicular to the axis of the workpiece, and means for moving the holder toward the workpiece opposite to the direction of rotation thereof, to move a portion of the angular edge of the tool into tangential engagement with the workpiece.

11. Apparatus according to claim 10 characterized further by said tool holder comprising a clamping block holding said tool, and means for pivoting th clamping block around an axis parallel to the axis of rotation of the workpiece.

12. Apparatus according to claim 11 wherein said clamping block pivot is positioned so that a line extending through said pivot and the point of engagement of the tool and the workpiece lies above the axis of rotation of the workpiece.

13. Apparatus according to claim 11 characterized further by resilient means associated with said clamping block for urging said tool against the workpiece.

14. Apparatus according to claim 13 characterized further by stop means for limiting the extent to which said clamping block can be moved by said resilient means when said tool is spaced from the workpiece.

15. Apparatus according to claim 14 characterized by said stop means positioning said clamping block so that a lower surface of said tool initially engages the workpiece tangentially when said tool holder is moved toward the workpiece.

16. A method of forming metal comprising rotating a workpiece having a raised portion forming an annular shoulder thereon, positioning a tool with an edge thereof at an angle relative to a plane through the shoulder which is perpendicular to the axis of rotation of the workpiece, moving the tool in a path toward the workpiece from a direction such that the workpiece rotates toward the tool and engaging the shoulder with the tool edge to apply a force against the shoulder having a component parallel to the axis of the workpiece to cause incremental portions of the shoulder to move outwardly from the axis of rotation, providing a cutting edge on the tool, and positioning the cutting edge to trim the extremity of the outwardly-extending portion of the shoulder as the shoulder portion is moved a predetermined distance away from the axis of rotation of the workpiece.

17. A method of forming metal comprising rotating a workpiece having a raised annular portion forming a pair of annular shoulders, moving a tool with diverging lower slanted edge portions toward and above the tool in a path lying in a plane transverse to the axis of rotation of the workpiece, engaging both of the shoulders with said diverging slanted edge portions of said tool and urging the shoulders of the workpiece toward one another and outwardly from the axis of rotation of the workpiece, providing a cutting edge on the tool extending between the ends of said slanted portions, and positioning the cutting edge to trim the extremity of the outwardly-extending portion of the annular portion as the outwardly-extending portion is moved a predetermined distance away from the axis of rotation of the workpiece.

18. A tool for extruding shoulders on a workpiece comprising a block having a notch of predetermined shape in one end thereof, said notch forming lower slanted edge portions on the block converging toward one another in a direction away from the end of the block, said block having a cutting edge at the end of the notch at a lower edge thereof extending between said slanted edge portions.

US. Cl. X.R.

P0405? UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 A55 ,850 I Dated July '8 9 9 Inventor) Robert C. Zeller and Warren W. Weible It is certified that error appears in the above-identified patent and that said Letters Patent are hereby sorrected as shown below:

In column 1, line M6, "when" should read where In column 2, line 11, "hing should read being In column 4, line 50, "it" should read ls line 67, "slides" should read --,s'1des In column 6, line 33, "tool" should read workpiece SIGNED M) V SEALED APR 2 8 1970 E .Attest:

wmxm 2. sum.

Edward M. Fletchflb commissioner of Patents Attesting Officer 

